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Old 09-19-2011, 05:12 PM   #58 (permalink)
Stick your neck out...
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Join Date: Jun 2011
Location: Essex UK
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Craig – thanks for the insight! I value your input, and obviously experience counts for a lot, but I knew this was a difficult challenge right from the start. My goal of 100mph is the same as your “70mph into 30mph headwinds”, or as near as makes no difference. The drag calcs (posted earlier) confirm that 100mph can be achieved with 11.5hp. The Honda C90 is 85cc and 7.5hp std, and with mild tuning (inc switch to programmable ECU and fuel injection) should reach this target power. I’ve planned for heat issues, and will use a fully ducted and fan-assisted airflow system. I would prefer to use a liquid cooled motor but there is nothing (that I am aware of) with a horizontal cylinder layout, which is an essential part of the low seat-height design. EDIT - looks like I've answered my own question in the reply below, Doh!
Jkv357 – that Aprilia does look good! My budget for this project would be overstretched to get something like that, and then I could never bring myself to cut it up! The C90 was the ideal start point just because I wouldn’t hesitate to cut it into pieces! Oh, and it’s a horizontal cylinder style. Allert’s bike (125cc, liquid cooled & fuel injected) would have been even better but they are still to valuable to “wreck”. But with a bit of luck I could fit that engine at a later date.
Project 100 link
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